rustc_typeck: move some obligation methods to Inherited.

Author: eddyb

src/librustc_typeck/check/assoc.rs

@@ -20,7 +20,6 @@ use rustc::util::common::ErrorReported;
 use syntax::ast;
 use syntax_pos::Span;
 
-use super::assoc;
 use super::{Inherited, FnCtxt};
 use astconv::ExplicitSelf;
 
@@ -227,7 +226,6 @@ fn compare_predicate_entailment<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
     tcx.infer_ctxt(trait_param_env, Reveal::UserFacing).enter(|infcx| {
         let inh = Inherited::new(infcx);
         let infcx = &inh.infcx;
-        let fulfillment_cx = &inh.fulfillment_cx;
 
         debug!("compare_impl_method: caller_bounds={:?}",
                infcx.parameter_environment.caller_bounds);
@@ -239,12 +237,11 @@ fn compare_predicate_entailment<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
                                                        infer::HigherRankedType,
                                                        &ty::Binder(impl_m_own_bounds.predicates));
         for predicate in impl_m_own_bounds {
-            let traits::Normalized { value: predicate, .. } =
+            let traits::Normalized { value: predicate, obligations } =
                 traits::normalize(&mut selcx, normalize_cause.clone(), &predicate);
 
-            fulfillment_cx.borrow_mut().register_predicate_obligation(
-                &infcx,
-                traits::Obligation::new(cause.clone(), predicate));
+            inh.register_predicates(obligations);
+            inh.register_predicate(traits::Obligation::new(cause.clone(), predicate));
         }
 
         // We now need to check that the signature of the impl method is
@@ -277,11 +274,9 @@ fn compare_predicate_entailment<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
         let impl_sig =
             impl_sig.subst(tcx, impl_to_skol_substs);
         let impl_sig =
-            assoc::normalize_associated_types_in(&infcx,
-                                                 &mut fulfillment_cx.borrow_mut(),
-                                                 impl_m_span,
-                                                 impl_m_body_id,
-                                                 &impl_sig);
+            inh.normalize_associated_types_in(impl_m_span,
+                                              impl_m_body_id,
+                                              &impl_sig);
         let impl_fty = tcx.mk_fn_ptr(ty::Binder(impl_sig));
         debug!("compare_impl_method: impl_fty={:?}", impl_fty);
 
@@ -291,11 +286,9 @@ fn compare_predicate_entailment<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
         let trait_sig =
             trait_sig.subst(tcx, trait_to_skol_substs);
         let trait_sig =
-            assoc::normalize_associated_types_in(&infcx,
-                                                 &mut fulfillment_cx.borrow_mut(),
-                                                 impl_m_span,
-                                                 impl_m_body_id,
-                                                 &trait_sig);
+            inh.normalize_associated_types_in(impl_m_span,
+                                              impl_m_body_id,
+                                              &trait_sig);
         let trait_fty = tcx.mk_fn_ptr(ty::Binder(trait_sig));
 
         debug!("compare_impl_method: trait_fty={:?}", trait_fty);
@@ -344,7 +337,7 @@ fn compare_predicate_entailment<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
 
         // Check that all obligations are satisfied by the implementation's
         // version.
-        if let Err(ref errors) = fulfillment_cx.borrow_mut().select_all_or_error(&infcx) {
+        if let Err(ref errors) = inh.fulfillment_cx.borrow_mut().select_all_or_error(&infcx) {
             infcx.report_fulfillment_errors(errors);
             return Err(ErrorReported);
         }
@@ -731,7 +724,8 @@ pub fn compare_const_impl<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
     debug!("compare_const_impl(impl_trait_ref={:?})", impl_trait_ref);
 
     tcx.infer_ctxt((), Reveal::UserFacing).enter(|infcx| {
-        let mut fulfillment_cx = traits::FulfillmentContext::new();
+        let inh = Inherited::new(infcx);
+        let infcx = &inh.infcx;
 
         // The below is for the most part highly similar to the procedure
         // for methods above. It is simpler in many respects, especially
@@ -761,31 +755,21 @@ pub fn compare_const_impl<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
         let trait_ty = tcx.item_type(trait_c.def_id).subst(tcx, trait_to_skol_substs);
         let mut cause = ObligationCause::misc(impl_c_span, impl_c_node_id);
 
-        let err = infcx.commit_if_ok(|_| {
-            // There is no "body" here, so just pass dummy id.
-            let impl_ty = assoc::normalize_associated_types_in(&infcx,
-                                                               &mut fulfillment_cx,
-                                                               impl_c_span,
-                                                               ast::CRATE_NODE_ID,
-                                                               &impl_ty);
+        // There is no "body" here, so just pass dummy id.
+        let impl_ty = inh.normalize_associated_types_in(impl_c_span,
+                                                        impl_c_node_id,
+                                                        &impl_ty);
 
-            debug!("compare_const_impl: impl_ty={:?}", impl_ty);
+        debug!("compare_const_impl: impl_ty={:?}", impl_ty);
 
-            let trait_ty = assoc::normalize_associated_types_in(&infcx,
-                                                                &mut fulfillment_cx,
-                                                                impl_c_span,
-                                                                ast::CRATE_NODE_ID,
-                                                                &trait_ty);
+        let trait_ty = inh.normalize_associated_types_in(impl_c_span,
+                                                         impl_c_node_id,
+                                                         &trait_ty);
 
-            debug!("compare_const_impl: trait_ty={:?}", trait_ty);
+        debug!("compare_const_impl: trait_ty={:?}", trait_ty);
 
-            infcx.sub_types(false, &cause, impl_ty, trait_ty)
-                 .map(|InferOk { obligations, value: () }| {
-                     for obligation in obligations {
-                         fulfillment_cx.register_predicate_obligation(&infcx, obligation);
-                     }
-                 })
-        });
+        let err = infcx.sub_types(false, &cause, impl_ty, trait_ty)
+            .map(|ok| inh.register_infer_ok_obligations(ok));
 
         if let Err(terr) = err {
             debug!("checking associated const for compatibility: impl ty {:?}, trait ty {:?}",
@@ -822,5 +806,7 @@ pub fn compare_const_impl<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
                                 &terr);
             diag.emit();
         }
+
+        // FIXME(#41323) Check the obligations in the fulfillment context.
     });
 }

src/librustc_typeck/check/compare_method.rs

@@ -129,7 +129,6 @@ use rustc_back::slice;
 use rustc_const_eval::eval_length;
 use rustc_const_math::ConstInt;
 
-mod assoc;
 mod autoderef;
 pub mod dropck;
 pub mod _match;
@@ -537,7 +536,7 @@ impl<'a, 'gcx, 'tcx> InheritedBuilder<'a, 'gcx, 'tcx> {
 }
 
 impl<'a, 'gcx, 'tcx> Inherited<'a, 'gcx, 'tcx> {
-    pub fn new(infcx: InferCtxt<'a, 'gcx, 'tcx>) -> Self {
+    fn new(infcx: InferCtxt<'a, 'gcx, 'tcx>) -> Self {
         Inherited {
             infcx: infcx,
             fulfillment_cx: RefCell::new(traits::FulfillmentContext::new()),
@@ -548,20 +547,55 @@ impl<'a, 'gcx, 'tcx> Inherited<'a, 'gcx, 'tcx> {
         }
     }
 
+    fn register_predicate(&self, obligation: traits::PredicateObligation<'tcx>) {
+        debug!("register_predicate({:?})", obligation);
+        if obligation.has_escaping_regions() {
+            span_bug!(obligation.cause.span, "escaping regions in predicate {:?}",
+                      obligation);
+        }
+        self.fulfillment_cx
+            .borrow_mut()
+            .register_predicate_obligation(self, obligation);
+    }
+
+    fn register_predicates(&self, obligations: Vec<traits::PredicateObligation<'tcx>>) {
+        for obligation in obligations {
+            self.register_predicate(obligation);
+        }
+    }
+
+    fn register_infer_ok_obligations<T>(&self, infer_ok: InferOk<'tcx, T>) -> T {
+        self.register_predicates(infer_ok.obligations);
+        infer_ok.value
+    }
+
     fn normalize_associated_types_in<T>(&self,
                                         span: Span,
                                         body_id: ast::NodeId,
-                                        value: &T)
-                                        -> T
+                                        value: &T) -> T
         where T : TypeFoldable<'tcx>
     {
-        assoc::normalize_associated_types_in(self,
-                                             &mut self.fulfillment_cx.borrow_mut(),
-                                             span,
-                                             body_id,
-                                             value)
+        let ok = self.normalize_associated_types_in_as_infer_ok(span, body_id, value);
+        self.register_infer_ok_obligations(ok)
     }
 
+    fn normalize_associated_types_in_as_infer_ok<T>(&self,
+                                                    span: Span,
+                                                    body_id: ast::NodeId,
+                                                    value: &T)
+                                                    -> InferOk<'tcx, T>
+        where T : TypeFoldable<'tcx>
+    {
+        debug!("normalize_associated_types_in(value={:?})", value);
+        let mut selcx = traits::SelectionContext::new(self);
+        let cause = ObligationCause::misc(span, body_id);
+        let traits::Normalized { value, obligations } =
+            traits::normalize(&mut selcx, cause, value);
+        debug!("normalize_associated_types_in: result={:?} predicates={:?}",
+            value,
+            obligations);
+        InferOk { value, obligations }
+    }
 }
 
 struct CheckItemTypesVisitor<'a, 'tcx: 'a> { tcx: TyCtxt<'a, 'tcx, 'tcx> }
@@ -1806,32 +1840,6 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
             .register_bound(self, ty, def_id, cause);
     }
 
-    pub fn register_predicate(&self,
-                              obligation: traits::PredicateObligation<'tcx>)
-    {
-        debug!("register_predicate({:?})", obligation);
-        if obligation.has_escaping_regions() {
-            span_bug!(obligation.cause.span, "escaping regions in predicate {:?}",
-                      obligation);
-        }
-        self.fulfillment_cx
-            .borrow_mut()
-            .register_predicate_obligation(self, obligation);
-    }
-
-    pub fn register_predicates(&self,
-                               obligations: Vec<traits::PredicateObligation<'tcx>>)
-    {
-        for obligation in obligations {
-            self.register_predicate(obligation);
-        }
-    }
-
-    pub fn register_infer_ok_obligations<T>(&self, infer_ok: InferOk<'tcx, T>) -> T {
-        self.register_predicates(infer_ok.obligations);
-        infer_ok.value
-    }
-
     pub fn to_ty(&self, ast_t: &hir::Ty) -> Ty<'tcx> {
         let t = AstConv::ast_ty_to_ty(self, ast_t);
         self.register_wf_obligation(t, ast_t.span, traits::MiscObligation);